Abstract: A method for monitoring a number of electrode surfaces of an electrode of the type used in an HF surgery device includes the steps, in a first stage of the method, of connecting one of the electrode surfaces to a current source and connecting a measuring unit via a first switch to at least two of the remaining electrode surfaces to be monitored and thereby forming measured values which are to be compared to each other for equality. In a second stage of the method, a different electrode surface is connected to the current source and the measuring unit is connected to different ones of the remaining electrode surfaces, and measured values are again obtained and compared for quality. The electrode surface which served as the auxiliary (i.e., current supplied) electrode in the first stage of the method may serve as one of the monitored electrode surfaces in the second stage. A circuit for practicing the method is also disclosed.

Abstract: A multipart planar electrode, suitable for use as a neutral electrode for an HF surgery device, has four sub-electrodes arranged on one side of a flexible, common carrier. At least three of these sub-electrodes have substantially the same area and at least two of the sub-electrodes have a limiting edge disposed parallel to and adjacent at least a portion of a separate edge of one of the remaining sub-electrodes. This insures that, if one of the sub-electrodes is used as an auxiliary electrode for a symmetry measurement of sub-currents, there will not be equality of the contact area of the electrodes with the patient's skin at the remaining sub-electrodes upon the occurrence of a straight-line release edge in an arbitrary direction. Because such equal areas will not occur, this will be detected by the symmetry measurement and an alarm indicating partial detachment of the electrode can be activated.

Abstract: A neutral electrode for a high frequency surgery device has three planar sub-electrodes, which are arranged side by side on a carrier consisting of insulating material. To improve monitoring of the contact of the sub-electrodes with the body of the patient, the two outer sub-electrodes have substantially triangular contact surfaces, with the respective hypotenuses of the triangular contact surfaces proceeding parallel to and spaced from each other, with a central, strip-shaped sub-electrode disposed between the hypotenuses of the outer sub-electrodes. The neutral electrode is intended for use with a monitoring system which will activate an alarm if the neutral electrode becomes detached from the patient to such an extent that the danger of injury to the patient exists. This is accomplished by monitoring a current or currents flowing through the patient between sub-electrodes.

Abstract: A neutral electrode for a high-frequency electrosurgical instrument comprises three partial electrodes arranged in a predetermined direction on an insulated carrier. The carrier has on one side which is parallel to the predetermined direction, an electrical line terminal. The terminal contains electrical lines leading to the partial electrodes. In accordance with the invention, the surface area of the partial electrodes decreases in the predetermined direction. The electrode is applied on the patient so that the predetermined direction points toward the site of the surgical procedure. In this way, the partial electrodes are essentially acted upon by identical fractions of high-frequency energy, so that reliable monitoring of the contact between the partial electrodes and the patient is possible.

Abstract: A neutral electrode comprising several partial electrodes having respective electrical connections disposed on a carrier having a link to which the electrical connections lead. In the link, and specifically asymmetrically to the connections, a first and a second opening are provided. When a connecting clamp is connected to the electrode, these openings are engaged by projections which are arranged on the inside surfaces of two clamping elements of the connecting clamp.

Abstract: An electrode of at least three elements, useful in particular as a neutral electrode for a high frequency surgical instrument. The electrode elements are placed on a common flexible carrier and are arranged symmetrically and rotationally displaced from each other with respect to an axis of symmetry which extends perpendicular from the carrier. Thus, application of the electrode to a patient with respect to an axis of rotation on the patient is not critical and safe monitoring of proper contact on the patient is ensured.

Abstract: An electrode, in a first embodiment, comprises three sub-electrodes which are of essentially triangular shape and form a rectangular contact surface. Preferably, two right-angular sub-electrodes and an acute isosceles sub-electrode lying in-between these are employed. In a second embodiment the electrode comprises three sub-electrodes of essentially rectangular shape. One sub-electrode is preferably formed in a T-shape, and the foot of the T lies between two other rectangular sub-electrodes.The electrode is preferably used as a neutral electrode in a HF-surgical apparatus. An associated monitoring circuit allows a rapid determination of whether the entire electrode or only a sub-electrode is in good electrical contact with the skin surface of a patient to which the surgical apparatus is being applied.

Abstract: A multi-element electrode comprises at least two flat partial electrodes which are arranged in juxtaposition to a pre-established direction. To simplify the fabrication of such an electrode and in particular to allow the use of cable conductors of equal length for attachment thereto, provision is made for the two partial electrodes to exhibit facing edges which are at an angle to the pre-established direction. Such a construction is advantageous in the case of a three-part electrode. The electrode is preferably the neutral electrode of an HF-surgical apparatus.